tamerlan tsarnaev. number two on the loose, a fugitive right now, believed to be armed and dangerous, described as a terrorist, he was caught on camera last night, he's been on the loose for several hours and all of boston, the entire city of boston surrounding suburbs in lockdown right now. >> that's right. abc news just spoke to those boys' father, he is in shock and implores his son to himself up. he told abc news, he said that he think his sons were set up and he said they were very nice kids, never touched explosives and never learned how to handle weapons. he said that his younger son is on the run and in hiding because he's also afraid, words from his father. never saw indication at all atwas capable of violence. we're reminded by brad garrett, our fbi specialing at, often these terrorist lead double lives. we begin with chief investigative brian ross, on the ground, all through the night in watertown, brian, a night of gunfire, bombs, police hunting down the terrorists right now. >> reporter: in